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Dec 21, 2015
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Types of Computers and
Computer Systems
Objectives
• You will be able to:– Define what is a computer– Differentiate between the different types of
computers– Explain the concept of Computer Systems – Demonstrate the concepts of: architecture,
specification, data, and processing– Define the concept of motherboard and mention the
main components of it (CPU, cards)– Differentiate between input and output functions and
devices.
What is a Computers?
• A computer: is an electronic device that:– Accepts information and instructions from
users– Manipulates the information according to the
instructions– Displays the information in some way– And Stores the information for retrieval later.
• Computers are classified by: size, speed and capabilities
Types of Computers?
1. Personal Computers
2. Hand-held Computers
3. Mainframe Computers
4. SupercomputersNote: Xbox and PlayStation are also computers
Personal Computers:
• Personal Computers: used by a single user for use in home or office. They are used for general computing tasks such as:
– Word processing– Manipulating numbers– Working with photographs or graphics– Exchanging email and accessing the Net
Personal Computers Examples:
• Desktop computer (designed to set compactly on a desk):
– Notebook (laptop): small and lightweight and designed for portability
– Tablet PC: designed for compatibility and includes the capability of recognizing ordinary handwriting on the screen
• Notebook is more expensive than Desktop, and Tablet PC is more expensive than notebook computers
Handheld Computers
• Handheld Computers: are small computers that fit in the palm of your hand with more limited capabilities than personal computers:
– PDA (Personal Digital Assistants): are used to maintain an electronic appointment book, address book, calculator, and notepad
• High-end PDA: All-in-one devices that can send and receive emails and make phone calls (e.g. iPhone)
– MP3 players: are used to store and play music (some models can play digital movies and television shows)
– Cell Phone: are used to make phone calls, store contact information, take and store digital photos, play video, store music. Built-in calculator. High-end cell phones can perform many of the same functions as PDA
Mainframe Computers
• Mainframe Computers: are used by larger business and government agencies to provide centralized storage, processing, and management of large amounts of data
• Its price varies from several hundred thousand dollars to several million dollars
Supercomputers
• Supercomputers: are the fastest and largest computers used by large corporations and government agencies when the tremendous volume of data would seriously delay processing on a mainframe computer.
• It could cost tens of millions dollars
Understanding Terminals
• When using mainframes or supercomputers each user inputs processing request and views output through a terminal or terminal emulator.
• Terminal: has a keyboard for input and a monitor for output, but process little or no data on its own.
• Terminal Emulator: a personal computer, workstation, or server that uses special software to imitate a terminal so that the PC can communicate with the mainframe or supercomputer for complex data processing.
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Computer System
• Computer System: includes computer Hardware and Software
• Hardware: the physical components of a computer
• Software: the intangible components of a computer system; the programs or the list of instructions that the computer needs to perform a specific task
Architecture and Specifications
• Architecture - Configuration: the design and construction of a computer
• Specification: the technical details about each hardware component
• Eg: a computer system might be configured to include a printer; the specification of the printer might be a print speed (8pages/1min), or the capacity to print in color
Data and Processing
The hardware and software of a computer system work together to process data
• Data: the words, numbers, figures, sounds, graphics that describe people, events, things, and ideas
• Processing: modifying the data• Processing tasks occur on the motherboard
which is located inside the computer and is the main electronic component of the computer
Motherboard
• Motherboard: a circuit board which is a rigid piece of insulating material with circuits, electrical paths, on it that control specific functions
Motherboard Processing Hardware
• Microprocessor or the Central Processing Unit (CPU):
• Consists of transistors and electronic
circuits on a silicon chip (an integrated
circuit embedded in semiconductor
material)• Mounted on the motherboard and is
responsible for executing instructions
to process information
Motherboard Processing Hardware
• Cards: are removable circuit boards that are inserted into slots in the motherboard to expand the capabilities of the motherboard
• Eg: Sound card translates the
digital audio information from the
computer into analog sounds
that the human ear can hear
Input and Output
• Input: data or instructions you type into the computer
• Output: the result of the computer processing input
• Peripheral Devices: components are needed to accomplish input, output, and storage functions
Input Devices
• Keyboard and mouse are input devices that are used to enter data and issue commands
• Commands: are input instructions that tell the computer how to process data (e.g. ms words commands)
Output Devices
• Output can be in many different forms:– Reports– Documents– Graphs– Sounds– Pictures
• The output forms are produced by output device e.g. monitor and printer
• The output created can be stored either inside the computer or in external storage device (e.g DVD)
Comparing CPU Speeds
• How fast a computer can process instructions depends partially on the speed of the microprocessor, which is determined by its:
– Clock Speed
– Word Size
– Cache Size– Whether it is single or dual core
Comparing CPU Speeds
• Clock Speed: is measured in megahertz (MHz), millions of cycles per second, or in gigahertz (GHz), billions of cycles per second
• Word Size: the amount of data the is processed at one time
• Dual-Core processor: has two processors on a single chip, can process information up to twice as fast as single-core processor (one with one processor on the chip)
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